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Using a noncommutative inspired Einstein-Euler-Heisenberg black hole, we analyse the associated graviton and light rings that together with the event horizon, provide the necessary components to build its shadow. An analysis of the angular…

General Relativity and Quantum Cosmology · Physics 2021-10-27 Marco Maceda , Alfredo Macías , Daniel Martínez-Carbajal

We discuss the horizon properties, shadow cast, and the weak gravitational lensing of charged rotating regular black holes, which in addition to mass ($M$) and rotation parameter ($a$) have an electric charge ($Q$) and magnetic charge…

General Relativity and Quantum Cosmology · Physics 2019-12-12 Rahul Kumar , Sushant G. Ghosh , Anzhong Wang

The astrophysical consequences of the presence of a quintessence scalar field on the evolution of the horizon and on the accretion disk surrounding a static black hole, in the Scalar-Vector-Tensor version of Modified Gravity (MOG), are…

General Relativity and Quantum Cosmology · Physics 2023-09-15 Haidar Sheikhahmadi , Saheb Soroushfar , S. N. Sajadi , Tiberiu Harko

The first images of black hole shadows open new possibilities to constrain modern extended gravity theories. We present the method of shadow background calculation for black hole solutions in the form of Taylor series where $g_{11} = -…

General Relativity and Quantum Cosmology · Physics 2022-09-07 V. Prokopov , S. Alexeyev , O. Zenin

In general relativity, the angular radius of the shadow of a black hole is primarily determined by its mass-to-distance ratio and depends only weakly on its spin and inclination. If general relativity is violated, however, the shadow size…

Recently, two new spherically symmetric black hole models with covariance have been proposed in effective quantum gravity. Based on these models, we use the modified Newman-Janis algorithm to generate two rotating quantum-corrected black…

General Relativity and Quantum Cosmology · Physics 2024-11-15 Zhenglong Ban , Jiawei Chen , Jinsong Yang

When the the shadow image of a supermassive black hole in the center of M87 was obtained a new era in the observational astrophysics began. The resolution improvement would allow to test extended gravity models at event horizon scales. We…

General Relativity and Quantum Cosmology · Physics 2020-08-26 S. O. Alexeyev , V. A. Prokopov

We examine the shadow of a rotating Kaluza-Klein black hole in Einstein gravity coupled to a Maxwell field and a dilaton. The size and the shape of the shadow depend on the mass, the charge, and the angular momentum of the compact object.…

General Relativity and Quantum Cosmology · Physics 2016-01-14 Leonardo Amarilla , Ernesto F. Eiroa

Gravity models given by higher-order scalar curvature corrections are believed to bear important consequences. The Einstein-Bel-Robinson gravity, with quartic curvature modification, motivated Sajadi et al to explore static spherically…

General Relativity and Quantum Cosmology · Physics 2024-04-11 B. Hamil , B. C. Lütfüoğlu

Inspired by the observations of supermassive black hole M87* in \emph{Event Horizon Telescope }(EHT) experiment, a remarkable surge in black hole physics is to use the black hole shadow's observables to distinguish general relativity (GR)…

General Relativity and Quantum Cosmology · Physics 2022-09-20 Yuan Meng , Xiao-Mei Kuang , Zi-Yu Tang

In this paper, we study the shadow and images of the accretion disk of Kerr-Newman (KN) black hole (BH) in modified gravity (MOG) theory by using backward ray-tracing method. And, the influence of spin parameter ($a$), charge ($Q$), and MOG…

General Relativity and Quantum Cosmology · Physics 2025-02-07 He-Bin Zheng , Meng-Qi Wu , Guo-Ping Li , Qing-Quan Jiang

Recent observations of the supermassive black holes M87* and Sgr A* by the Event Horizon Telescope (EHT) have opened new avenues for testing gravity theories through black hole shadow observables. These observations offer a means to…

General Relativity and Quantum Cosmology · Physics 2025-05-05 Mohsen Fathi , Yassine Sekhmani

In this paper, the shadow casted by the rotating black hole inspired by noncommutative geometry is investigated. In addition to the dimensionless spin parameter $a/M_{0}$ with $M_{0}$ black hole mass and inclination angle $i$, the…

General Relativity and Quantum Cosmology · Physics 2015-08-18 Shao-Wen Wei , Peng Cheng , Yi Zhong , Xiang-Nan Zhou

A regular rotating MOG (modified gravity) compact object is derived that reduces to the Kerr black hole when the parameter $\alpha=0$. Physical consequences of the dark compact object, which is regular everywhere in spacetime for $\alpha >…

General Relativity and Quantum Cosmology · Physics 2021-02-15 J. W. Moffat

The recent Event Horizon Telescope (EHT) observations of the M87* have led to a surge of interest in studying the shadow of black holes. Besides, investigation of time evolution and lifetime of black holes helps us to veto/restrict some…

General Relativity and Quantum Cosmology · Physics 2023-02-14 S. H. Hendi , Kh. Jafarzade , B. Eslam Panah

We study the shadows of disformal black holes in vector-tensor Galileons modified gravity. Our analysis shows that the apparent image of the black hole in the observer's sky is non-spherical and cuspy, which is in contrast to the Kerr and…

General Relativity and Quantum Cosmology · Physics 2018-01-25 Tsvetan Vetsov , Galin Gyulchev , Stoytcho Yazadjiev

This study explores spherically symmetric non-linear electrodynamics black holes and their effects on light propagation. We derive the governing metric, revealing radial coordinate dynamics within the event horizon. We analyze photon…

General Relativity and Quantum Cosmology · Physics 2024-02-06 Akhil Uniyal , Sayan Chakrabarti , Mohsen Fathi , Ali Övgün

In this manuscript, we provide a comprehensive study of gravitational lensing by dark compact objects predicted by a Modified Gravity (MOG) based on the Scalar-Vector-Tensor action, and the aim is to analyze new insights into the nature of…

General Relativity and Quantum Cosmology · Physics 2025-03-07 Nagina Rehman , Zoe C. S. Chan , Mubasher Jamil , Mustapha Azreg-Aïnou

We consider a simple spherical model consisting of a Schwarzschild black hole of mass $M$ and a dark matter of mass $\Delta M$ around it. The general formula for the radius of black-hole shadow has been derived in this case. It is shown…

General Relativity and Quantum Cosmology · Physics 2019-06-05 R. A. Konoplya

The Event Horizon Telescope (EHT) has guided strong-field gravitational physics by providing the first direct images of the supermassive black holes M87* and Sagittarius A*. The EHT observations offer unprecedented opportunities to test…

General Relativity and Quantum Cosmology · Physics 2026-04-16 Towheed Ahmad Nengroo , Shafqat Ul Islam , Sushant G. Ghosh